System and Method for Automatic Throttling of Resources in an Information Handling System Chassis

ABSTRACT

Systems and methods for automatic throttling of resources in an information handling system are disclosed. A method may include determining whether a first throttling condition exists, the first throttling condition existing when a chassis management controller fails to communicate a clock or synchronization signal to one or more devices in an information handling system chassis for a particular duration of time. The method may also include determining whether a second throttling condition exists, the second throttling condition existing when the chassis management controller fails to communicate data to one or more devices in the information system handling chassis. The method may further include throttling a resource in the information handling system chassis if at least one of the first throttling condition and the second throttling condition exists.

TECHNICAL FIELD

The present disclosure relates in general to information handling systemchassis management, and more particularly to a system and method forautomatic throttling of resources in an information handling systemchassis.

BACKGROUND

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

In certain implementations, many individual self-contained informationhandling systems (e.g., server blades) may be placed together in asingle chassis or a plurality of chasses. Such implementations allow fora high concentration of computing resources in a relatively smallphysical space, and are often used in applications that require asignificant amount of computing resources (e.g., web servers, fileservers, mail servers, etc.).

One disadvantage of high-density computing systems is that such systemsoften require large amounts of power. Such power requirements may leadto increased operational costs, as well as undesired heating of elementsin the high-density computing system that could cause performancedegradation. To combat this problem, modern high-density computingsystems employ devices (e.g., chassis management controllers) to monitorand/or control power usage. Such power-management devices may permitcertain resources to be “throttled” or placed in a low-power mode toallow such power to be allocated to other computing resources in thesame chassis or another chassis.

One problem associated with the use of such chassis managementcontrollers occur when the chassis management controller goes offlinedue to removal, firmware update, failover condition, or other reason,causing the chassis to become unmanaged. When this occurs, the chassismay “assume” that all processing and memory resources are operating at amaximum level, thus causing chassis cooling fans to spin up by defaultto ensure worst-case scenario cooling requirements. Such spinning up offans may claim power that may otherwise be used by computing resources(e.g., processors and/or memories) in the same chassis and/or in otherchasses. Reclaiming such power may permit more computing resources to beutilized.

SUMMARY

In accordance with the teachings of the present disclosure,disadvantages and problems associated with power management in aninformation handling system chassis have been substantially reduced oreliminated.

In accordance with one embodiment of the present disclosure, a methodfor automatic throttling of resources in an information handling systemchassis is provided. The method may include determining whether a firstthrottling condition exists, the first throttling condition existingwhen a chassis management controller fails to communicate a clock orsynchronization signal to one or more devices in an information handlingsystem chassis for a particular duration of time. The method may alsoinclude determining whether a second throttling condition exists, thesecond throttling condition existing when the chassis managementcontroller fails to communicate data to one or more devices in theinformation system handling chassis. The method may further includethrottling a resource in the information handling system chassis if atleast one of the first throttling condition and the second throttlingcondition exists.

In accordance with another embodiment of the present disclosure, asystem for automatic throttling of resources in an information handlingsystem chassis may include at least one resource and a throttle modulecommunicatively coupled to the at least one resource. The throttlemodule may be operable to determine whether a first throttling conditionexists, the first throttling condition existing when a chassismanagement controller fails to communicate a clock or synchronizationsignal to one or more devices in an information handling system chassisfor a particular duration of time. The throttle module may also beoperable to determine whether a second throttling condition exists, thesecond throttling condition existing when the chassis managementcontroller fails to communicate data to one or more devices in theinformation system handling chassis. The throttle module may further beoperable to communicate a signal to throttle a resource if at least oneof the first throttling condition and the second throttling conditionexists.

In accordance with a further embodiment of the present disclosure, aninformation handling system may include a processor, a memorycommunicatively coupled to the processor, and a throttle modulecommunicatively coupled to the at least one resource. The throttlemodule may be operable to determine whether a first throttling conditionexists, the first throttling condition existing when a chassismanagement controller fails to communicate a clock or synchronizationsignal to one or more devices in an information handling system chassisfor a particular duration of time. The throttle module may also beoperable to determine whether a second throttling condition exists, thesecond throttling condition existing when the chassis managementcontroller fails to communicate data to one or more devices in theinformation system handling chassis. The throttle module may further beoperable to communicate a signal to throttle at least one of theprocessor and the memory if at least one of the first throttlingcondition and the second throttling condition exists.

Other technical advantages will be apparent to those of ordinary skillin the art in view of the following specification, claims, and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present embodiments and advantagesthereof may be acquired by referring to the following description takenin conjunction with the accompanying drawing, in which like referencenumbers indicate like features, and wherein the FIGURE illustrates ablock diagram of an example information handling system chassis, inaccordance with the present disclosure.

DETAILED DESCRIPTION

Preferred embodiments and their advantages are best understood byreference to the FIGURE, wherein like numbers are used to indicate likeand corresponding parts.

For the purposes of this disclosure, an information handling system mayinclude any instrumentality or aggregate of instrumentalities operableto compute, classify, process, transmit, receive, retrieve, originate,switch, store, display, manifest, detect, record, reproduce, handle, orutilize any form of information, intelligence, or data for business,scientific, control, entertainment, or other purposes. For example, aninformation handling system may be a personal computer, a PDA, aconsumer electronic device, a network storage device, or any othersuitable device and may vary in size, shape, performance, functionality,and price. The information handling system may include memory, one ormore processing resources such as a central processing unit (CPU) orhardware or software control logic. Additional components or theinformation handling system may include one or more storage devices, oneor more communications ports for communicating with external devices aswell as various input and output (I/O) devices, such as a keyboard, amouse, and a video display. The information handling system may alsoinclude one or more buses operable to transmit communication between thevarious hardware components.

For the purposes of this disclosure, computer-readable media may includeany instrumentality or aggregation of instrumentalities that may retaindata and/or instructions for a period of time. Computer-readable mediamay include, without limitation, storage media such as a direct accessstorage device (e.g., a hard disk drive or floppy disk), a sequentialaccess storage device (e.g., a tape disk drive), compact disk, CD-ROM,DVD, random access memory (RAM), read-only memory (ROM), electricallyerasable programmable read-only memory (EEPROM), and/or flash memory, aswell as communications media such wires, optical fibers, microwaves,radio waves, and other electromagnetic and/or optical carriers; and/orany combination of the foregoing.

The FIGURE illustrates a block diagram of an example informationhandling system chassis 100 (referred to herein as “chassis 100”), inaccordance with the present disclosure. Chassis 100 may be an enclosurethat serves as a container for various information handling components,and may be constructed from steel, aluminum, plastic, and/or any othersuitable material. Although the term “chassis” is used, chassis 100 mayalso be referred to as a case, cabinet, tower, box, enclosure, and/orhousing. In certain embodiments, chassis 100 may be configured to holdand/or provide power to a plurality of server blades and/or othercomponents (e.g., a “rack mount” system). As depicted in the FIGURE,chassis 100 may include blades 102, one or more chassis managementcontrollers 106, and fans 120.

Each chassis management controller 106 may include any system, device orapparatus operable to monitor the power requirements of and control theoperation of one or more components of chassis 100. As shown in theFIGURE, each chassis management controller 106 may generate a clockand/or synchronization signal (e.g., the signals labeled CLK/SYNC in theFIGURE) for blades 102 and/or other components of chassis 100. Inaddition, each chassis management controller 106 may also communicatedata to blades 102 and/or other components of chassis 100 (as shown bythe signal bus labeled as DATA in the FIGURE). In certain embodiments,such data may be communicated via a time division multiplexed (TDM)communication bus (e.g., bus 107). For example, an active chassismanagement controller 106 may determine that certain resources withinchassis 100 may require more power than other resources, and mayappropriately cause throttling of those resources requiring less power.As used herein, the term “resources” may be used to generally refer toblades 102, processors 103, and memories 104. As another example, anactive chassis management controller 106 may receive a signal fromanother chassis indicating that the other chassis requires more power.

Accordingly, each chassis management controller 106 may throttleresources in chassis 100 to allow such power to be used by the otherchassis. Each chassis management controller 106 may throttle suchcomponents (e.g., blades 102) by communicating appropriate signals tothe components (e.g., via bus 107 referenced above). Additionally, eachchassis management controller 106 may be configured to monitorparameters of chassis 100 (e.g., temperature, system stress, etc.) andcontrol the operation of fans 120 (e.g., by communication via bus 107referenced above) to cool resources in chassis 100 and/or throttleresources in response to the detection of such parameters (e.g.,throttling in response to detection of a high temperature).

Each blade 102 may comprise an information handling system. In certainembodiments, one or more blades 102 may be a server (e.g., a bladeserver). In such embodiments, each blade 102 may be mounted in asuitable slot and/or interface of chassis 100. In the FIGURE, variouscomponents of one blade 102 are depicted. However, other blades 102 ofchassis 100 may have similar or identical components. As depicted in theFIGURE, one or more blades 102 may include a processor 103, a memory104, a current monitor 108, one or more sensors 110, a baseboardmanagement controller 112, and a throttle module 114. Although theFIGURE depicts chassis 100 having six blades 102, chassis 100 may haveany suitable number of blades 102.

Processor 103 may comprise any system, device, or apparatus operable tointerpret and/or execute program instructions and/or process data, andmay include, without limitation a microprocessor, microcontroller,digital signal processor (DSP), application specific integrated circuit(ASIC), or any other digital or analog circuitry configured to interpretand/or execute program instructions and/or process data. In someembodiments, processor 103 may interpret and/or execute programinstructions and/or process data stored in memory 104 and/or anothercomponent of chassis 100. Although the FIGURE depicts that blade 102comprises a single processor 103, blade 102 may include any suitablenumber of processors 103.

Memory 104 may be communicatively coupled to processor 103 and maycomprise any system, device, or apparatus operable to retain programinstructions or data for a period of time. Memory 104 may compriserandom access memory (RAM), electrically erasable programmable read-onlymemory (EEPROM), a PCMCIA card, flash memory, magnetic storage,opto-magnetic storage, or any suitable selection and/or array ofvolatile or non-volatile memory that retains data after power to blade102 and/or chassis 100 is turned off. Although the FIGURE depicts memory104 as a component integral to blade 102, one or more memories 104 mayreside external to blade 102.

Current monitor 108 may include any system, device or apparatusconfigured to monitor and/or detect the current being used by chassis100, blade 102 and/or individual components thereof. Current monitor 108may also be configured to compare the monitored current against acurrent threshold and communicate a signal (e.g., the signal labeledCURRENT_THROTTLE in the FIGURE) indicating that the threshold has beenexceeded (e.g., CURRENT THROTTLE asserted when the threshold has beenexceeded, unasserted otherwise). In certain embodiments, thecommunication of such signal may cause the throttling of blade 102and/or one or more other resources in chassis 100, as described ingreater detail below.

Sensors 110 may include any collection of one or more systems, devices,or apparatuses operable to sense one or more operating parametersassociated with chassis 100, blade 102, and/or its individual componentsthereof. For example, sensors 110 may include a temperature sensor(e.g., an electronic thermostat or thermometer) to detect thetemperature of the air in chassis 100 or the temperature of one or moreof the components of chassis 100. Such sensed parameters may becommunicated to baseboard management controller 112 of blade 102 forfurther processing.

Baseboard management controller 112 may be any system, device, and/orapparatus operable to control and/or manage blade 102 and/or itsindividual components. In certain embodiments, baseboard managementcontroller 112 may be configured to provide an out-of-band managementinterface between chassis 100 and/or blade 102 and a remote system andthat allows monitoring and management of chassis 100 and/or blade 102from the remote system. In certain embodiments, baseboard managementcontroller 112 may include a Dell Remote Access Controller (DRAC).Baseboard management controller 112 may allow a user remote to chassis100 and/or blade 102 to manage chassis 100, blade 102, and/or and thecomponents thereof as if the user were sitting at a local console. Asshown in the FIGURE, baseboard management controller 112 may receiveremote commands and signals from sensors 110. Based on at least thesereceived signals, baseboard management controller 112 may output one ormore control signals to other components of blade 102, including asignal (e.g., signal THROTTLE_OUT_OF_BAND as depicted in the FIGURE)indicating that blade 102 or one or more of its components is to bethrottled (e.g., if a remote command was received to throttle) and/or ifsensors 110 sense one or more parameters (e.g., a high temperature)indicating that blade 102 or one or more of its components should bethrottled (e.g., THROTTLE_OUT_OF_BAND asserted when throttling is tooccur, not asserted otherwise). Baseboard management controller 112 mayalso communicate a signal (e.g., signal ENABLE_CMC_AUTO_THROTTLE asdepicted in the FIGURE) indicating whether blade 102 is operating in alow-power configuration (e.g., ENABLE_CMC_AUTO_THROTTLE asserted if notin a lower-power configuration, not asserted otherwise).

Throttle module 114 may be any system, device or apparatus operable toreceive signals from current monitor 108, sensors 110, baseboardmanagement controller 112, a chassis management controller 106 and/orother components of chassis 100, and based on at least such signals,determine whether or not blade 102 or one or more of its components isto be throttled. For example, in the particular embodiment depicted inthe FIGURE, throttle module 114 may receive the CLK/SYNC signal and DATAfrom one of the chassis management controllers 106, along with thesignals CURRENT_THROTTLE, THROTTLE_OUT_OF_BAND, andENABLE_CMC_AUTO_THROTTLE discussed above, and determine whether to issuea signal to throttle one or more components of blade 102 based on atleast such received signals. In certain embodiments, throttle module 114may be implemented in whole or part with a programmable logic device(PLD) or a complex programmable logic device (CPLD).

As depicted in the FIGURE, throttle module 114 may include chassismanagement controller (CMC) translation module 116. CMC translationmodule 116 may receive the CLK/SYNC signal and DATA from an activemanagement controller 106, and based on at least the CLK/SYNC signal andDATA from the active chassis management controller 106, determinewhether DATA includes a command and/or signal to throttle one or morecomponents of blade 102, and may communicate a signal (e.g., signalTHROTTLE_CMC as shown in the FIGURE) indicating whether DATA includes acommand and/or signal to throttle.

In addition, CMC translation module 116 may receive the CLK/SYNC signaland DATA from one or more management controllers 106, and based on atleast the CLK/SYNC signal and DATA, determine whether all chassismanagement controllers 106 are offline (e.g., due to removal, firmwareupdate, failover condition, or other reason). For example, if CMCtranslation module 116 detects that clock or synchronization signalCLK/SYNC is not received (which may indicate that management controller106 is offline), CMC translation module 116 may communicate a signalindicating that no CLK/SYNC was detected (e.g., signal LOSS_OF_CLK/SYNCdepicted in the FIGURE; asserted if no CLK/SYNC detected, otherwise notasserted).

In certain embodiments, a determination that no CLK/SYNC signal wasdetected may be made if no CLK/SYNC signal is available for a particularamount of time (e.g., 50 ms or more). Similarly, if CMC translationmodule 116 detects that chassis management controllers 106 are notcommunicating data (e.g., when DATA is communicated on bus 107,detection of a “void” or indication that chassis management controllers106 are not participating on the bus), CMC translation module 116 maycommunicate a signal indicating that chassis management controllers 106are not communicating data (e.g., signal CMC_VOID_DETECT depicted in theFIGURE; asserted if data not communicated, otherwise not asserted).

Thus, if either of signals LOSS_OF_CLK/SYNC or CMC_VOID_DETECT isasserted, chassis management controllers 106 may be offline, and one ormore resources of chassis 100 may be throttled. However, there arecertain scenarios in which, despite either of signals LOSS_OF_CLK/SYNCor CMC_VOID_DETECT being asserted, it may not be desirable to throttleblade 102 and/or resources in chassis 100. For example, if blade 102 isoperating in a low-power configuration (e.g., as would be the case ifthe ENABLE_CMC_AUTO_THROTTLE signal is not asserted), blade 102 mayalready be operating in a low-power state and may not need throttling,or might suffer from excessive performance degradation if power providedto such resources is further reduced. Accordingly, throttle module 114may include logic (e.g., AND gates 117) that may override theLOSS_OF_CLK/SYNC and/or CMC_VOID_DETECT signals in low-powerconfigurations. Thus, the logical AND of LOSS_OF_CLK/SYNC andENABLE_CMC_AUTO_THROTTLE may produce intermediate signal X, while thelogical AND of CMC_VOID_DETECT and ENABLE_CMC_AUTO_THROTTLE may produceintermediate signal Y.

Throttle module 114 may also include logic (e.g., OR gate 118) thatdetermines whether blade 102 is to be throttled, based on at least thesignals CURRENT_THROTTLE, THROTTLE_OUT_OF_BAND, and THROTTLE_CMCdiscussed above, along with the intermediate signals X and Y discussedabove. The logical OR of the signals X, Y, CURRENT_THROTTLE,THROTTLE_OUT_OF_BAND, and THROTTLE_CMC may produce another signal (e.g.,signal THROTTLE shown in the FIGURE) indicative of whether blade 102 isto be throttled (e.g., THROTTLE asserted if throttling to occur,otherwise not asserted).

Fans 120 may include one or more mechanical or electro-mechanical fanused for cooling purposes. In certain embodiments, fans 120 may drawcool air into chassis 100 from the outside, expel warm air from insidechassis 100, and/or move air across a heatsink to cool one or moreparticular components of chassis 100.

Using the methods and systems disclosed herein, problems associatedconventional approaches to managing power consumption in an informationhandling system chassis have been reduced or eliminated. For example,because the methods and systems disclosed may allow for resources to beplaced in a throttled state upon detecting that a chassis is without anonline management controller, chasses may be provided in which fans donot enter an assumed worst-case scenario when a chassis becomesunmanaged.

Although the present disclosure has been described in detail, it shouldbe understood that various changes, substitutions, and alterations canbe made hereto without departing from the spirit and the scope of theinvention as defined by the appended claims.

1-20. (canceled)
 21. A method for automatic throttling of resources inan information handling system chassis, comprising: determining whethera first throttling condition exists, the first throttling conditionexisting when the resource is not in a low-power configuration;determining whether a second throttling condition exists, the secondthrottling condition existing when an out-of-band command has beenreceived to throttle the resource; and throttling a resource in theinformation handling system chassis if at least one of the firstthrottling condition and the second throttling condition exists.
 22. Amethod according to claim 21, further comprising: determining whether athird throttling condition exists, the third throttling conditionexisting when a chassis management controller fails to communicate aclock or synchronization signal to one or more devices in an informationhandling system chassis for a particular duration of time; andthrottling the resource in the information handling system chassis if atleast one of the first throttling condition, the second throttlingcondition, and the third throttling condition exists.
 23. A methodaccording to claim 21, further comprising: determining whether a fourththrottling condition exists, the fourth throttling condition existingwhen the chassis management controller fails to communicate data to oneor more devices in the information system handling chassis; andthrottling the resource in the information handling system chassis if atleast one of the first throttling condition, the second throttlingcondition, and the fourth throttling condition exists.
 24. A methodaccording to claim 21, further comprising: determining whether a fifththrottling condition exists, the fifth throttling condition existingwhen an electric current in the information handling system chassis hasexceeded a predetermined threshold; and throttling the resource in theinformation handling system chassis if at least one of the firstthrottling condition, the second throttling condition, and the fifththrottling condition exists.
 25. A method according to claim 21, furthercomprising: determining whether a sixth throttling condition exists, thesixth throttling condition existing when a command has been communicatedby the chassis management controller to throttle the resource; andthrottling the resource if at least one of the first throttlingcondition, the second throttling condition, and the sixth throttlingcondition exists.
 26. A method according to claim 21, wherein theresource includes a host, a processor, or a memory.
 27. A methodaccording to claim 21, wherein at least one of determining whether thefirst throttling condition exists and determining whether the secondthrottling condition exists includes monitoring a time divisionmultiplexed (TDM) bus.
 28. A system for automatic throttling ofresources in an information handling system chassis, comprising: atleast one resource; a throttle module communicatively coupled to atleast one resource, the throttle module operable to: determine whether afirst throttling condition exists, the first throttling conditionexisting when the resource is not in a low-power configuration;determine whether a second throttling condition exists, the secondthrottling condition existing when an out-of-band command has beenreceived to throttle the resource; and communicate a signal to throttlea resource if at least one of the first throttling condition and thesecond throttling condition exists.
 29. A system according to claim 28,the throttle module further configured to: determine whether a thirdthrottling condition exists, the third throttling condition existingwhen a chassis management controller fails to communicate a clock orsynchronization signal to one or more devices in an information handlingsystem chassis for a particular duration of time; and communicate thesignal to throttle the resource if at least one of the first throttlingcondition, the second throttling condition, and the third throttlingcondition exists.
 30. A system according to claim 28, the throttlemodule further configured to: determine whether a fourth throttlingcondition exists, the fourth throttling condition existing when thechassis management controller fails to communicate data to one or moredevices in the information system handling chassis; and communicate thesignal to throttle the resource if at least one of the first throttlingcondition, the second throttling condition, and the fourth throttlingcondition exists.
 31. A system according to claim 28, the throttlemodule further configured to: determine whether a fifth throttlingcondition exists, the fifth throttling condition existing when anelectric current in the information handling system chassis has exceededa predetermined threshold; and communicate the signal to throttle theresource if at least one of the first throttling condition, the secondthrottling condition, and the fifth throttling condition exists.
 32. Asystem according to claim 28, the throttle module further configured to:determine whether a sixth throttling condition exists, the sixththrottling condition existing when a command has been communicated bythe chassis management controller to throttle the resource; andcommunicate the signal to throttle the resource if at least one of thefirst throttling condition, the second throttling condition, and thesixth throttling condition exists.
 33. A system according to claim 28,wherein the resource includes a host, a processor, or a memory.
 34. Asystem according to claim 28, the throttle module further configured todetermine whether the first throttling condition exists and determinewhether the second throttling condition exists by monitoring a timedivision multiplexed (TDM) bus communicatively coupled to the throttlemodule.
 35. An information handling system, comprising: a processor; amemory communicatively coupled to the processor; and a throttle modulecommunicatively coupled to at least one of the processor and the memory,the throttle module operable to: determine whether a third throttlingcondition exists, the third throttling condition existing when theinformation handling system is not in a low-power configuration;determine whether a fourth throttling condition exists, the fourththrottling condition existing when an out-of-band command has beenreceived to throttle the resource; and communicate a signal to throttleat least one of the processor and the memory if at least one of thefirst throttling condition and the second throttling condition exists.36. An information handling system according to claim 35, the throttlemodule further configured to: determine whether a third throttlingcondition exists, the third throttling condition existing when a chassismanagement controller fails to communicate a clock or synchronizationsignal to one or more devices in an information handling system chassisfor a particular duration of time; communicate the signal to throttle atleast one of the processor and the memory if at least one of the firstthrottling condition, the second throttling condition, and the thirdthrottling condition exists.
 37. An information handling systemaccording to claim 35, the throttle module further configured to:determine whether a second throttling condition exists, the secondthrottling condition existing when the chassis management controllerfails to communicate data to one or more devices in the informationsystem handling chassis; and communicate the signal to throttle at leastone of the processor and the memory if at least one of the firstthrottling condition, the second throttling condition, and the fourththrottling condition exists.
 38. An information handling systemaccording to claim 35, the throttle module further configured to:determine whether a fifth throttling condition exists, the fifththrottling condition existing when an electric current in theinformation handling system chassis has exceeded a predeterminedthreshold; and communicate the signal to throttle at least one of theprocessor and the memory if at least one of the first throttlingcondition, the second throttling condition, and the fifth throttlingcondition exists.
 39. An information handling system according to claim35, the throttle module further configured to: determine whether a sixththrottling condition exists, the sixth throttling condition existingwhen a command has been communicated by the chassis managementcontroller to throttle the information handling system; and communicatethe signal to throttle at least one of the processor and the memory ifat least one of the first throttling condition, the second throttlingcondition, and the sixth throttling condition exists.
 40. An informationhandling system according to claim 35, the throttle module furtherconfigured to determine whether the first throttling condition existsand determining whether the second throttling condition exists bymonitoring a time division multiplexed (TDM) bus communicatively coupledto the throttle module.